TypeMock Interface Cast Problem

Hi all,

How does TypeMock deal with casting?

For example:

My Code

...
myClass
{
private IToyota _myToyota;

...

IVehicle myVehicle;
myVehicle = _myToyota as IVehicle;

if(myVehicle != null)
     myVehicle.ShutDownEngine();

...
}

Now here is the test code I would write:

MockObject mockToyota = MockManager.MockObject(typeof(IToyota));
myClassAccessor._myToyota = mockToyota.object as IToyota;

My questions are:

1) Whenever my code under test runs to the casting as IVehicle, myVehicle is null because the casting did not succeed, and I cannot check if ShutDownEngine() is called. How would I mock such a casting?

2) How would I expect a call to ShutDownEngine()?

Any suggestions would be greatly appreciated!

Thanks,

YFC